I had similar experiences a year ago with the emulation of fork in Windows (Windows 7 Home Premium with Service Pack 1).
Running the tests of Test::TCP (version 1.11 and 1.12) on Windows resulted often in a blocking Perl interpreter. Sometimes the system reached at state, that it must be restarted.
I started trying to isolate the problem and this is so far I came: https://rt.cpan.org/Public/Bug/Display.html?id=66016#txn-910155.
My experiences/conclusion using perlfork - Perl's fork() emulation in Windows, are:
- There is stochastic involved. Two identical calls (expected to give the same result) can give different results. What I understand is the problem in the implementation of the Windows API and not in the Perl implementation.
- In some cases the processes running the Perl interpreter are blocking (coming in an unwanted state).
- Sometimes the problem is not solved by restarting the Perl interpreter. Is there some missing initializations in the Perl interpreter?
- In some rare situations the total system (not just the process running the Perl interpreter) is affected, and must be restarted. Sometimes it even must be restated using power down/up. The isolation between processes and the operating system in Windows has some weakness?
The questions which worries me are:
- Is it advisable to use the Perl's fork() emulation in Windows in “production” code?
- Is it enough to run the test of Perl modules just once or how many times are they needed to be run?